Which statement is not true about how various conditions will effect the activity of an enzyme?
a. optimal temperatures generally enhance the activity of an enzyme.
b. above a certain range of temperatures, the protein of an enzyme is denatured.
c. a change in ph can cause an enzyme to be denatured.
d. an enzyme's activity will decrease with an increase in substrate concentration.
e. when sufficient substrate is available, the active site of an enzyme will nearly always be occupied.

Option (d).

Explanation:

Enzymes are bio-catalyst that can increase the rate of a biochemical reactions occurring in the body of living organisms. The enzymes work at the optimum temperature and pH conditions.

The activity of the enzyme may also be affected by the substrate concentration. The increase in the substrate concentration increases the enzymatic activity at the level and maximum when the enzymes occupy all the site. The enzyme activity will never decrease with the increase of substrate concentration.

Thus, the correct answer is option (d).

"d.) carbon dioxide and hydrogen sulfide"

i don't know. if i were you, i would search it up online : d